Mujitsu and Tairaku's Shakuhachi BBQ

purehappiness · 2009-01-20 06:41:02

I am wondering how important bore diameter is to the shakuhachi. I recently made a first attempt flute and the bore was 1/2 inch for a 1.8 size. I had a very hard time trying to get sounds out of it. When I did it sounded great but it was difficult. Well, anyway, I cracked it last night trying to enlarge the bore. Now, for my second attempt, with the proper bore diameter. I hope. Any help would be greatly appreciated.

Thank you

jaybeemusic · 2009-01-20 08:37:56

It's actually VERY important....

here are some general guidelines....of course there are exceptions to every rule....

small bore = smaller sound, brighter, higher pitch, usually faster response (when the note starts) easier to fine tune....

big bore = big sound, more airy, darker, lower pitch, slower response, more difficult to get a well playing instrument but a lot of people really like the wide bore sound... that's kind of the idea behind the Taimu style flutes....

Jacques

edosan · 2009-01-20 10:04:19

Typical bore diameter for a 'normal' 1.8 (ie, not a big-bore flute) is 20-24mm; that's well over 3/4 inch. That's likely a good deal of your problem in getting sound out of the flute. Takes a lot more precision and care to get the sound, and it won't take much wind without dropping out.

purehappiness · 2009-01-20 10:39:10

Yes, I seemed to going into the second octave very easily on some notes. So a larger bore will make it eaiser to play. I will have to go bamboo hunting soon. If only I could afford a well made one but for now this will have to do.

Mujitsu · 2009-01-20 10:41:45

The bore width to length ratio (aspect ratio) has a strong influence on the tone of a flute. There is a window of thin to wide A.R. which will work for shakuhachi. Too thin and the low end suffers. Too wide and the high end suffers. Each extreme has its own unique sound. The average width at the top of a 1.8 is about 2cm or a little over 3/4". A bore of 1/2" for a 1.8 will make it difficult in the bottom end. Sounds like you've deduced that already by trial and error! (Sorry, just realized Ed already posted this!)

It's not easy to make good shakuhachi at any width. However, if you start making flutes with an A.R. somewhere in the middle (about 2cm) for 1.8, you'll have a better chance of tuning and playability falling into place. After some experience making flutes this size, you'll be better equipped to handle the challenges should you decide to experiment with thinner or wider A.R.

Here is an averaged bore profile of a 1.8. Notice how it starts at a bore diameter of 2cm. If you stay close to these specs you'll be off to a good start.

A search for "aspect ratio" on the forum will pull up a lot of information on this.

purehappiness · 2009-01-20 10:56:47

Thanks. This clears up a lot for me. My first flute was made from a bamboo pole I already had at home. Now I know what to look for.I am learning.

Thanks again.

Benjamin · 2009-03-17 20:04:52

While we are on the subject of aspect ratio, I have a couple of questions that I think ken could be able to answer. I have been making 2 longer flutes (both 2.4) and I got out my girlfriends electric tuner to see where they were pitched at and I was a little shocked to find that they were both pitched at G. Wouldn't that be more suited to a 2.8 flute? They are pretty wide bored, the outside diameter is 38-40 mm with a wall thickness of 7 to 8 mm. Both of these flutes have joints and was trying to figure out if I should fill the bore with putty. I just plastered a 1.8 flute with great sucess and that brought the pitch right into D in both octaves. I guess I was just wondering if I should try to utilize the wide bore and stay with the G pitch, or fill up the bore and shoot for a higher tuning?

edosan · 2009-03-17 20:12:28

Benjamin wrote:
While we are on the subject of aspect ratio, I have a couple of questions that I think ken could be able to answer. I have been making 2 longer flutes (both 2.4) and I got out my girlfriends electric tuner to see where they were pitched at and I was a little shocked to find that they were both pitched at G. Wouldn't that be more suited to a 2.8 flute? They are pretty wide bored, the outside diameter is 38-40 mm with a wall thickness of 7 to 8 mm. Both of these flutes have joints and was trying to figure out if I should fill the bore with putty. I just plastered a 1.8 flute with great sucess and that brought the pitch right into D in both octaves. I guess I was just wondering if I should try to utilize the wide bore and stay with the G pitch, or fill up the bore and shoot for a higher tuning?

http://www.shakuhachiforum.com/viewtopi … 2668#p2668

[Located by typing 'aspect ratio' into the Forum search engine, where there are a lot of posts on this subject, this being one of the more germaine.]

Mujitsu · 2009-03-17 21:36:11

Benjamin wrote:
I have been making 2 longer flutes (both 2.4) and I got out my girlfriends electric tuner to see where they were pitched at and I was a little shocked to find that they were both pitched at G. Wouldn't that be more suited to a 2.8 flute? They are pretty wide bored, the outside diameter is 38-40 mm with a wall thickness of 7 to 8 mm.

Benjamin,

A wider bore to length ratio results in a lower pitched fundamental. So, it's not unusual for a wider bore 2.4 to play lower than A.

Ken

Mujitsu and Tairaku's Shakuhachi BBQ

#1 2009-01-20 06:41:02

How important is bore diameter?

#2 2009-01-20 08:37:56

Re: How important is bore diameter?

#3 2009-01-20 10:04:19

Re: How important is bore diameter?

#4 2009-01-20 10:39:10

Re: How important is bore diameter?

#5 2009-01-20 10:41:45

Re: How important is bore diameter?

#6 2009-01-20 10:56:47

Re: How important is bore diameter?

#7 2009-03-17 20:04:52

Re: How important is bore diameter?

#8 2009-03-17 20:12:28

Re: How important is bore diameter?

Benjamin wrote:

#9 2009-03-17 21:36:11

Re: How important is bore diameter?

Benjamin wrote:

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